Telephone-transmitter.



G. N. QUINBY, JR. TELEPHONE TRANSMITTER.

APPLICATION TILED JULY 24, 1909.

Patented Apr. 19, 1910.

q Vihwon:

GEORGE N. QUINBY, JR., OF. NORTH PROVIDENCE, EI'IODE ISLAND.

TELEPHONE-TRANSMITTER.

Specification of Letters Patent.

Patented Apr. 19, 1910 Application filed July 24, 1909. Serial No. 509,298.

, To all whom it may concern:

Be it known that -l, Gnonon N. Qmnnr, Jr., a cit-lzen'of the United States, residing at North Providence, in the county of Providence and State of Rhode Island, have invented new and useful Improvements in Telephone-Transmitters, of which the following is a specification.

This invention relates to improvements in telephone transmitters, the object of the invention being to provide a construction insuring a clearer tone and freedom from the objectionable noises ordinarily produced by againsta mica washer 7 the vibration of the line wires and the con- .tact or movementof parts of connected telephone instruments or other noises in the vicinity of the instrument.

The invention consists of the features of construction, combination and arrangement of parts hereinafter fully described and claimed, reference being had to the accompanying drawing, in which Figure 1 is a vertical front to rear section through a telephone transmitter embodying my invention. Fig. 2 is a rear elevation of the front of the transmitter casing and the parts connected therewith. Fig. 3 is a transverse section through the electrode casing.

Referring to the drawing, 1 designates the body of the casing of a transmitter of the adjust-able type, and 2 the front of'the casing carrying the mouth piece 3. As shown, the front or cover 2 is provided with rearwardly extending flanges at which fitwithin the body 1 and may be secured thereto by screws or other fastenings, in the ordinary 'llhe diaphragm 5 is inclosed in the annular space formed by the flanges a and is provided around its periphery with the usual elastic" dampening ring 6, which bears resting against the inner face of the body of the cover 2. Secured to the flanges 4 are the usual dampening springs 8 which bear against the rear face of the diaphragm to limit the vibratory movements thereof.

Extending transversely within the body 1 and secured at its ends to the flanges 4 of the cover 2 is a bracket plate 9, preferably formed of brass, and which is thus a fixture of and removable with the cover and the diaphragm. The central portion of this bracket plate is provided with a rearward-1y extending U-shaped offset 10, which projects some distance rearwardly from the rear faecof the diaphragm. The offset 10 is provided as a partial housing and protector a chambered rear or body. portion. 12, prefer ably formed of aluminum and having a rearwardly extending central boss 13 provided with a screw threaded bore and a forwardly projecting externally threaded flan go l-"l. The rear electrode 15 is inclosed within the casing and bears against the rear wall thereof and is provided with the usual carbon facing 16 and has projecting from the rear face thereof a threaded stem 17 extending through the threaded bore of the boss 13 and provided with a binding nut 18. The

for the electrode easing 11,-which consists of front electrode 20 is of less diameter than i the interior of the casing and is provided with the usual carbon facing 21. The outer or front face of this electrode bears against a inica disk 22- clampcd peripherally a gainst the front face of the flange 14; by an internally threaded clamping ring 23, preferably formed of brass. From said electrode 20 projects a screw stud 214 extending through the disk 22 and engaged by a washer 25,

whereby said electrode is clamped to the disk. The stud Z-l is provided with a reduced threaded stem 26, which extends through an opening in the center of the diaphragm 5 and is provided with clamping and jam nuts 27 and 28 to clamp the diaphragm. against the front surface of the washer 25, by which theelectrode casing is fixed to and supported solely from the diaphragm.

The inner wall of the electrode casing is provided with the usueldining 29, and the arrangement of the elcetrodes therein is such as to provide an intervening space or chamber for a. body of carbon or other similar granular resistaiiccmaterial 30, which is influenced to transmit the electrical impulses from one electrode to the other in the vibrations of the diaphragm The opening in the diaphragm through which the stem 26 projects extends at an outward and downward angle, so that the electrode casing will he supported in an upwardly and forwardly inclined position when the transmitter is horizontally disposed, the deter fac'c of the washer 25 being of tapered or conical form to secure a firm clamping engagement beti'veen the parts and to permit the electrode casing to assume the described position;

It will be apparent from the foregoing dej scrlptlon that both the electrode casing and contactwith the ron and compactin bottom of the e ectrode casing and becoming from contact with the 'front electrode, as is liable to happenwhen 'sitions of thetransmitter the rear electrode are free from either mechanical or electrical connection with the of which braclnat 9, the -ofi'setportion 10 simply serves as a partial housing -or in- .closure for said electrode casing; to prevent possible injury thereto in the andling or movements of the transmitter. The purpose of arranging the electrode casing in a foristo cause the-pan holes of the body ofcarbon 30 to rest. by

wardly tilted position gravity at all times in full contact withthe front electrode, so as and perfect transmission of the vibrations of the well as to prevent the carbon from settling in a solid mass toward the partially withdrawn the electrode casing is normally'arranged in a horizontal position. --In the ordinary con struction of telephone transmitter in which the electrode casing is supported in a,nor-

mally horizontal position arallel with the diaphragm, the settling o the carbonarticles and their. artial withdrawal om 't' electrode causes the free particles, when the transmitter is swung up or down, to scrape against the surface of said electrode,

'andit will and a of the pothe carbon will be maintained in contact with the front elecbe apparent that in any trode and prevented from-packing, .with

, better results in the. transmission of the vibrations.

Secured to the rear face of one of the ends of the bracket is a block 31 of suitable'insulating material which carries azconducting terminal 32 to which the transmitter cord is in practice connectedr To this terminal is also soldered or otherwise secured an insulated conductin wire- 33 which is clamped by the nut 18 m'engagement with the electrode casing and rear electrode stem 17. A second insulated conducting wire 34:

is-soldered or otherwise secured-at its ends to the washer25 ofthe front electrode and to one of the flanges 4 or some other suitable portion of the cover-.2 of the transmitter 55 I In the ordinary construction of transmitter of this type the terminal wires are ordinarily connected with the terminal 32 and the respective electrodes,.and the electrode casing 15 either supported by the bracket 9 or the rear electrode stem 17 is connected therewith. -As aresult, any sound vibra tions of loud volume or high intensity are increased involume or intensity by the vibrations of thebifacket plate and associated ments, or

to secure a sensitive diaphragm to the rear electrode as causing an objectionable. sound which interferes with theclear transmission of the vocal impulses. 'jection my .construction avoids This ob .nected with oneof the electrodes metallic parts of .the transmitter. Any

sounds, therefore, produced by the contact or movement of parts of connected instrufrom the vibrations of the line wires," are ntensified by'the transmission of amplified vibrations to the diaphragms, thus obscuring the vocal impulses and vibrations which are frequently rendered inaudible. constructionovercomes this objection, as, the electrodes are wholly disconnected fromthe metallic bracket and are electrically connected with the transmitter casin through the single wire 34:, which is secure to the cover 2, t e vibratory action of which is comparatively slight and is reduced or rendered m'l. by the dampening ring 6, allow-' icalortion.-

2. n a telephone transmitter, the combi-' natlon of a casing, a cover therefor provided with'a mouth piece, a diaphragm supported by the cover, a bracket'secured to the rear of the cover and having a rearwardly projecting-ofiset, an electrode casing partially mclosed b said ofiset, said casing being-provided",wit spaced electrodes and an mterposed body of ranular material and being secured *at a ownwardly, upwardly and. forwardly inclined position to the diaphragm, a terminal connected with and insulated from the bracket, a conductor connecting said terminal with the rear electrode, and a conductor connecting the front elec-'- trode with the cover.

3. -In a telephone transmitter, a transmitter casing, a removable cover therefor, a diaphragm mounted on said cover, a bracket secured to the cover and having a rearwardly offset central .portion,'an electrode casing mounted solely inan inclined posi tion upon the diaphragm and partially pro-.

jecting into said offset portion, a -terminal upon and insulated from the bracket con-' and a connection between the cover and the other "electrode.

In testimony whereof I aifix my signature '125 in presence of two witnesses.

GEORGE. N. QUINBY, JR.

Witnesses:

GEORGE N. QUINBY, THOMAS ANenLL. 

